Background
TCP and UDP are the protocols on which all Internet applicationsdepend. TCP and UDP, in turn, depend on IP. IP is the glue that joinsthe world's diverse collection of hosts, LANs and WANs into a singlebig virtual network. Without IP, the Internet as we know it would notexist.
Every machine that connects to the Internet must have a uniqueaddress. The current version if IP, version 4, uses 32-bitaddresses. In theory, 32 bits results in many addresses (over 4billion), but in practice only a fraction of the addresses can beused. The Internet is growing exponentially. In January 1993 therewere an estimated 1.3 million machines; by January 1996, the numberhad reached 9.5 million [Reference]. There iswidespread agreement within the Internet community that the Internetwill run out of addresses early in the next century. The debate is notif, but when.
IP Version 6
IP Version 6 (IPv6) is the specific protocol chosen by the IETF as theInternet's Next-Generation IP. IPv6 uses 128-bit addresses, to insuresufficient addresses to last well into the 21st Century and beyond.Given that IP had to change to accomodate bigger addresses, the IPv6standardization effort also extends and improves on known limitationsof IPv4. Specifically, IPv6 has the following advantages:
- Essentially unlimited address space
- Simplified autoconfiguration; machines can plug into a network,generate their own addresses without manual configuration, and gainfull Internet access
- IPv6 header is designed for optimized processing
- Standard set of security features all IPv6 nodes must implement
- Native multicast support
- Support to automatically renumber entire networks
Status of IPv6
The specifications for the core pieces IPv6 protocols have been issuedas Proposed Standards by the IETF, and all major vendors (host androuter) are known to be doing IPv6 implementations. Indeed, the UNH Interoperability Lab hostedIPv6 "testathons" in February and June of 1996 for vendors to test outthere implementations. Sun, HP, Digital, IBM (AIX), Bay Networks andIpsilon have participated. Both Sun and Digital have prototypeimplementations that folks can download from the Internet for testingpurposes. More information on implementations can be found hereFor More Information
For information on the official current status of IPv6, the variousdraft documents the WG is developing, pointers to the mailing list(and its archives), etc., visit the IETF's officialIPng Working Group page. Another good collection of semi-officialmaterial can be found at the playgroundarchive, which is maintained by one of the IPng WGco-chairs.For background on the issues that lead to the decision to chose IPv6as the next standard, consult RFC 1752 and itsextensive set of references. The book "IPng Internet Protocol NextGeneration" (S. Bradner, A. Mankin editors, 1995. (ISBN 0-201-63395-7)contains similar information, but edited and distilled for easierreading.
If you think it's about time you learned something about IPv6, butdon't know where to start, there is already at least one book on IPv6that delves into the technical detail of the protocols: "IPv6 The NewInternet Protocol" (Christian Huitema, 188pp., 1995. ISBN0-13-241936).
If you would rather go straight to the RFCs, I'd suggest starting withthe following (in approximate priority order).
- "Internet Protocol, Version 6 (IPv6) Specification",S. Deering, R. Hinden, RFC 1883,01/04/1996.
- "IP Version 6 Addressing Architecture", R. Hinden,S. Deering, RFC 1884, 01/04/1996.
- "Neighbor Discovery for IP Version 6 (IPv6)", T. Narten,E. Nordmark, W. A. Simpson, Internet Draft (Approved as ProposedStandard by IESG, awaiting publication as an RFC) draft-ietf-ipngwg-discovery-04.txt.
- "IPv6 Stateless Address Autoconfiguration", S. Thompson, T. Narten,Internet Draft (Approved as Proposed Standard by IESG, awaitingpublication as an RFC)
.draft-ietf-addrconf-ipv6-auto-07.txt.
